The present invention relates to novel nargenicin related compounds which can inhibit DnaE and have antibacterial, particularly antimycobacterial activity against Mycobacterium tuberculosis. The present invention also relates to method for inhibiting growth of mycobacterial cells as well as a method of treating mycobacterial infections by Mycobacterium tuberculosis by administering an antimycobacterially effective amount of nargenicin or a nargenicin-related compound and/or their pharmaceutically acceptable salts.